Unit 1 Lesson 5 States of MatterEssential Question: How do particles in solids, liquids, and gases move?

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Particles in MotionHow do particles move in solids, liquids, and gases?• The kinetic theory of matter states that all matter is made

of tiny particles that are in constant motion.

• The state of matter is determined by how much particles move and how often they bump into each other.

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How do particles move in solids, liquids, and gases?• A solid is a substance with a definite volume and shape.

Particles are close together and do not move freely.

• A liquid is a substance with a definite volume but not a definite shape.

• A gas is a substance that does not have a definite volume or shape.

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Shape Up!How does particle motion affect the

properties of solids, liquids, and gases?• Particles in a solid vibrate but remain in fixed positions.

• Solids cannot easily change shape or volume.

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How does particle motion affect the properties of solids, liquids, and gases?

• Liquids take the shape of their container. Particles in a liquid are close together but not tightly arranged.

• Particles in liquids slide past each other, creating flow.

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How does particle motion affect the properties of solids, liquids, and gases?

• Particles in gases are far apart.

• The space between gas particles can change easily.

• Gases take on the shape of their container.

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What happens when substances change state?

• The process in which a solid becomes a liquid is called melting.

• As a solid is heated, if the vibrations in the particles are fast enough, the particles break loose and slide past one another.

• When temperatures of a liquid are lowered, causing a solid to form, it is called freezing.

• Lower temperatures cause the particles to move slowly enough for the attractions between them to cause the liquid to become a solid.

• Water freezes at 0°C, but other substances can freeze at room temperature.

• When substances lose or gain energy, one of two things can happen to the substance: its temperature can change or its state can change.

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What happens when substances change state?

•When substances lose or gain energy, one of two things can happen to the substance:

• its temperature can change • or its state can change.

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